Pathology of Head Injury

Question 1

Commonest cause of traumatic head injury in the UK?

Answer 1

Road traffic accidents and alcohol related incidents including assaults

Question 2

What are the primary and secondary concerns after trauma to the head?

Answer 2

• Primary: focal/diffuse brain trauma

- Secondary: hypotension, hypoxia, infection, haematoma

Question 3

How do scores on the glasgow coma scale correlate with severity of head injury?

Answer 3

Score out of 15, 3 the lowest

13-15 - mild injury
9-12 - moderate injury
3-8 - severe injury

Question 4

What are some significant post trauma complications patients may experience

Answer 4

• Permanent physical disability
• Post traumatic epilepsy
• Intracranial infection
• Psychiatric illness
• Chronic subdural haemorrhage
• Punch drunk dementia

Question 5

How can a natural disease cause head trauma?

Answer 5

Can cause collapse of the patient that results in head injury

Question 6

Describe the relationship of the different layers of meninges to the brain and skull

Answer 6

• Dura: adhered to the inner surface of the skull
• Arachnoid: envelopes the brain
• Pia: adhered to surface of the brain, goes into sulci

Question 7

Why is the scalp quite vulnerable to laceration from blunt force impact?

Answer 7

Because it is attached to the skull making tearing associated with blunt force impact more likely

Question 8

Types of skull fracture?

Answer 8

• Linear
• Depressed
• Comminuted
• Ring
• Contre-coup

Question 9

Where do linear skull fractures usually occur?

Answer 9

Usually temporo-parietal from fall/blow to side of head

Becomes “hinge” fracture if continues to skull base

Question 10

Describe a depressed skull fracture

Common post-trauma complications?

Answer 10

Focal impact pushes skull fragments inwards, damages meninges and blood vessels

Risk of meningitis and post-traumatic epilepsy

Question 11

Describe a comminuted skull fracture

Answer 11

Fracture resulting in a fragmented skull

Question 12

Describe a ring skull fracture

Answer 12

Fracture around the foramen magnum

Usually due to fall landing on feet, pushes the skull and spine together

Question 13

Describe a contre-coup skull fracture

Answer 13

Fracture of the orbital plates caused by a fall onto the back of the head

Question 14

What are the types of intracranial haemorrhage? Where are they located in relation to the skull/meninges?

Answer 14

• Extradural: between dura and skull
• Subdural: Beneath dura but above arachnoid
• Subarachnoid: subarachnoid space

Question 15

How does an intracranial haemorrhage result in neurological symptoms/death?

Answer 15

• Increases intracranial pressure (ICP) which compresses the brain causing symptoms
• Too high an ICP can cause pressure on the brainstem which causes herniation of the cerebellar tonsils into the foramen magnum, causing death

Question 16

What is the most common cause of extradural haemorrhage? Which artery is most often involved with the bleed?

Answer 16

• Skull fracture most common cause (80-90% cases)

- Usually caused by bleeding from middle meningeal artery

Question 17

Which blood vessels are usually torn in subdural haemorrhage? What can put you at risk of these vessels rupturing?

Answer 17

• Emissary veins
• Atrophic (smaller) brains can cause the veins to get stretched more easily, any rotational/shearing force can make the vessels vulnerable

Question 18

Which type of haemorrhage can be chronic, particularly in the elderly? Often presents as confusion

Answer 18

• Subdural haemorrhage

Question 19

What is the “Lucid Interval”? In what types of haemorrhages can it be seen?

Answer 19

• Lucid interval: victim initially seems to be okay, but can catastrophically deteriorate later
• Can occur in extradural and subdural haemorrhage

Question 20

Most common cause of subarachnoid haemorrhage?

Answer 20

Natural disease - rupture of cerebral artery

Question 21

What does traumatic basal SAH tell you on a forensic report?

Answer 21

Blow to upper part of side of neck, causing abrupt rotational movement of the head leading to rupture of vertebro-basilar circulation

Question 22

Causes of intrinsic brain injury?

Answer 22

• Cerebral oedema (can develop in minutes, often malignant, causes raised ICP)
• Cerebral contusion/laceration: direct mechanical damage to brain substance

Question 23

Other than haemorrhage, what type of CNS damage can trauma do? (badly worded, probably try fix this)

Answer 23

Diffuse traumatic axonal injury

Clinically often results in the patient going into comatose, will probably have concussion and maybe retrograde amnesia after trauma